Clearing antifreeze from a water tank

[Lou Jacobs]

I've just taken ownership of a boat that was properly winterized with antifreeze being run into the just about empty water tank. I've pumped it all out of the two sink taps, and have filled the tank. How do I conveniently ensure that I've flushed any residial antifreeze from the system? I'd rather not have to pump 30 gallons through the sink taps. Do I let it run out of the tank into the bilge? There must be a better way.

 

[Bill O'Donovan]

Well...

You still have to flush it out of the pipes. Go have a beer while the taps are running.

 

[MW]

tank drain

I have heard of some folks draining the tanks by removing the water "feeder" pipe and draining it into the bilge-that's fine but as Bill points out-you still need to flush the pipes. This is the process which I have used for years-be glad that you have water under preasure-I still recall those days of doing this with a manual sink pump-but then again the tank was smaller-happy sailing.

 

[Andy]

It may be a two beer job

The procedure I use is to pump the bulk of the antifreeze using the system's pump and galley/head sink faucets,then add enough water to the tank to run the pump while allowing the source to keep adding water to the tank. When the pink disappears, I shut off the source and pump the tank. In your case, you might achieve peace of mind by emptying the tank, as Bill suggested, by whatever means and flushing the system. The beer aspect is debateable I suppose but why tempt fate?Andy

 

[Lou]

Who said I have a pressure system?

Nope. Unfortunately, I will be pumping by hand if this is the best way to do it.

 

[Warren]

Emptying tank

Here's a method to empty "most" of the tank, if the boat is on the hard: put a hose into the tank (try to get it as far into the tank as it will go). Connect the the other end to a water source/spigot. Fill the hose until it is putting water INTO your tank. Shut off the water. Now disconnect the hose from the water source, and make sure that end of the hose is lower than your water tank. Bingo. The water will siphon OUT of your tank. You will still have some residual water to pump out by hand, but this method really does the lion's share of the work, particularly if you don't have a pressure water system.